Ik i am thank you tho xoxo
The height at which the mass will be lifted is; 3 meters
<h3>How to utilize efficiency of a machine?</h3>
Formula for efficiency is;
η = useful output energy/input energy
We are given
η = 60% = 0.6
Input energy = 4 KJ = 4000 J
Thus;
0.6 = useful output energy/4000
useful output energy = 0.6 * 4000
useful output energy = 2400 J
Work done in lifting mass(useful output energy) = force * distance moved
Useful output energy = 800 * h
where h is height to lift mass
Thus;
800h = 2400
h = 2400/800
h = 3 meters
Read more about Machine Efficiency at; brainly.com/question/3617034
#SPJ1
Sorry bro people do this22.2 pls
Answer:
a)
, b) ![T_{H} = 327.78\,K\,(54.63\,^{\textdegree}C)](https://tex.z-dn.net/?f=T_%7BH%7D%20%3D%20327.78%5C%2CK%5C%2C%2854.63%5C%2C%5E%7B%5Ctextdegree%7DC%29)
Explanation:
a) The coefficient of performance of a reversible refrigeration cycle is:
![COP_{R} = \frac{T_{L}}{T_{H}-T_{L}}](https://tex.z-dn.net/?f=COP_%7BR%7D%20%3D%20%5Cfrac%7BT_%7BL%7D%7D%7BT_%7BH%7D-T_%7BL%7D%7D)
Temperatures must be written on absolute scales (Kelvin for SI units, Rankine for Imperial units)
![COP_{R} = \frac{275.15\,K}{286.15\,K-275.15\,K}](https://tex.z-dn.net/?f=COP_%7BR%7D%20%3D%20%5Cfrac%7B275.15%5C%2CK%7D%7B286.15%5C%2CK-275.15%5C%2CK%7D)
![COP_{R} = 25.014](https://tex.z-dn.net/?f=COP_%7BR%7D%20%3D%2025.014)
b) The respective coefficient of performance is determined:
![COP_{R} = \frac{Q_{L}}{Q_{H}-Q_{L}}](https://tex.z-dn.net/?f=COP_%7BR%7D%20%3D%20%5Cfrac%7BQ_%7BL%7D%7D%7BQ_%7BH%7D-Q_%7BL%7D%7D)
![COP_{R} = \frac{8.75\,kW}{10.5\,kW-8.75\,kW}](https://tex.z-dn.net/?f=COP_%7BR%7D%20%3D%20%5Cfrac%7B8.75%5C%2CkW%7D%7B10.5%5C%2CkW-8.75%5C%2CkW%7D)
![COP_{R} = 5](https://tex.z-dn.net/?f=COP_%7BR%7D%20%3D%205)
But:
![COP_{R} = \frac{T_{L}}{T_{H}-T_{L}}](https://tex.z-dn.net/?f=COP_%7BR%7D%20%3D%20%5Cfrac%7BT_%7BL%7D%7D%7BT_%7BH%7D-T_%7BL%7D%7D)
The temperature at hot reservoir is found with some algebraic help:
![COP_{R} \cdot (T_{H}-T_{L})=T_{L}](https://tex.z-dn.net/?f=COP_%7BR%7D%20%5Ccdot%20%28T_%7BH%7D-T_%7BL%7D%29%3DT_%7BL%7D)
![T_{H}-T_{L} = \frac{T_{L}}{COP_{R}}](https://tex.z-dn.net/?f=T_%7BH%7D-T_%7BL%7D%20%3D%20%5Cfrac%7BT_%7BL%7D%7D%7BCOP_%7BR%7D%7D)
![T_{H} = T_{L}\cdot \left(1+\frac{1}{COP_{R}} \right)](https://tex.z-dn.net/?f=T_%7BH%7D%20%3D%20T_%7BL%7D%5Ccdot%20%5Cleft%281%2B%5Cfrac%7B1%7D%7BCOP_%7BR%7D%7D%20%20%5Cright%29)
![T_{H} = 273.15\,K \cdot \left(1+\frac{1}{5} \right)](https://tex.z-dn.net/?f=T_%7BH%7D%20%3D%20273.15%5C%2CK%20%5Ccdot%20%5Cleft%281%2B%5Cfrac%7B1%7D%7B5%7D%20%20%5Cright%29)
![T_{H} = 327.78\,K\,(54.63\,^{\textdegree}C)](https://tex.z-dn.net/?f=T_%7BH%7D%20%3D%20327.78%5C%2CK%5C%2C%2854.63%5C%2C%5E%7B%5Ctextdegree%7DC%29)